3,138 Studies Reviewed. 77.4% Found Biological Effects. The Evidence is Clear.

Microwave irradiation affects radial-arm maze performance in the rat.

Bioeffects Seen

Lai H, Horita A, Guy AW, · 1994

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Microwave radiation at cell phone-level exposures impaired rats' spatial memory by disrupting key brain neurotransmitter systems.

Plain English Summary

Summary written for general audiences

Researchers exposed rats to microwave radiation at 2450 MHz for 45 minutes, then tested their maze navigation abilities. The exposed rats showed significant memory problems, getting lost more often and struggling to learn. This suggests microwave exposure may impair brain function and spatial memory.

Why This Matters

This study represents a critical piece of evidence in understanding how radiofrequency radiation affects brain function. The exposure level used (0.6 W/kg SAR) is well within the range of what people experience from cell phones and other wireless devices during typical use. What makes this research particularly significant is that it identified specific neurochemical pathways involved in the memory impairment - this wasn't just behavioral observation but actual disruption of brain neurotransmitter systems. The fact that the memory problems could be reversed with specific drugs targeting these neurotransmitter systems provides strong evidence that the microwaves were directly affecting brain chemistry, not just causing stress or heating effects. This research adds to a growing body of evidence suggesting that our daily exposure to wireless radiation may be subtly but meaningfully affecting cognitive function.

Exposure Details

SAR
0.6 W/kg
Power Density
1 µW/m²
Source/Device
2450 MHz
Exposure Duration
45 min

Exposure Context

This study used 1 µW/m² for radio frequency:

This study used 0.6 W/kg for SAR (device absorption):

Building Biology guidelines are practitioner-based limits from real-world assessments. BioInitiative Report recommendations are based on peer-reviewed science. Check Your Exposure to compare your own measurements.

Where This Falls on the Concern Scale

Study Exposure Level in ContextA logarithmic scale showing exposure levels relative to Building Biology concern thresholds and regulatory limits.Study Exposure Level in ContextThis study: 1 µW/m²Extreme Concern1,000 uW/m2FCC Limit10M uW/m2Effects observed in the Slight Concern range (Building Biology)FCC limit is 10,000,000x higher than this exposure level

Study Details

The aim of this study is to investigate Microwave irradiation affects radial-arm maze performance in the rat.

After 45 min of exposure to pulsed 2450 MHz microwaves (2 microseconds pulses, 500 pps, 1 mW/cm2, av...

These data indicate that both cholinergic and endogenous opioid neurotransmitter systems in the brain are involved in the microwave-induced spatial memory deficit.

Cite This Study
Lai H, Horita A, Guy AW, (1994). Microwave irradiation affects radial-arm maze performance in the rat. Bioelectromagnetics 15(2):95-104, 1994.
Show BibTeX
@article{h_1994_microwave_irradiation_affects_radialarm_1133,
  author = {Lai H and Horita A and Guy AW and},
  title = {Microwave irradiation affects radial-arm maze performance in the rat.},
  year = {1994},
  
  url = {https://pubmed.ncbi.nlm.nih.gov/8024608/},
}

Quick Questions About This Study

Researchers exposed rats to microwave radiation at 2450 MHz for 45 minutes, then tested their maze navigation abilities. The exposed rats showed significant memory problems, getting lost more often and struggling to learn. This suggests microwave exposure may impair brain function and spatial memory.